2022 Volume 36 Issue 5 Pages 691-700
Objective: To determine the characteristics of solid mass lesions identified on thyroid gland mass screening.
Subjects and Methods: Ultrasonography was performed for 5,714 individuals who did not undergo treatment and who were aged 51.3 ± 10.5 years, including 3,971 women and 1,743 men, from April 1, 2018. The maximum diameter and characteristics of the solid masses with and without diffuse abnormalities, such as swelling, inhomogeneity, and/or coarseness, were evaluated.
Results: Abnormal findings were identified in 2,333 individuals (40.8%), including solid masses in 1,551 (27.1%), cystic lesions in 1,002 (17.5%), and diffuse abnormalities in 467 (8.2%). Further check-ups were recommended in 136 cases, resulting in diagnosis of papillary carcinoma in 9 cases (0.2%). The diameters of the solid masses showed a log-normal distribution (p<0.0001) and averaged 6.8 (3.2–14.6) mm (mean ± 2SD). The masses were single in 1,054 individuals (68.0%) and multiple in 497 (32.0%). Cystic degeneration and swelling more frequently occurred when the masses were multiple or > 20 mm in size. The incidence and number of solid masses increased accordingly with age without a significant increase in size.
Conclusions: Mass screening with ultrasonography identified a high prevalence of solid mass lesions in the thyroid gland. The log-normal distribution of their sizes without significant increases with age, despite the increase in number, suggests that the small mass lesions were benign, provided they had no characteristics suggestive of papillary carcinoma. A small proportion of these solid masses may develop into adenomatous goiter or follicular neoplasia.
